Process of distilling wood for the manufacture of charcoal and saving of by-products.



No. 674,49l. Patented May 2|, I90l.

c.,w. BIILFINGER. A

PROCESS OF DISTILLING WDODFOR THE MANUFACTURE OF SHARE-DAL AND SAVING 0F BY-PRODUCTS.

(Application filed Feb. 24, 1900.)

3 Sheets-Sheet I.

VENUE SI e/wbo wi t/mow Wu 0 m: norms nzrzns co PnoTo-umo. WASHINGTON o. c.

No. 674,491. Patented May. 2|, I901. c. w-. BILFINGER.

PROCESS OF DISTILLING WOOD FOR THE MANUFACTURE OF CHARCOAL AND SAVING OF BY-PRODUOTS.

(Application filed Feb. 24, 1900.

(No Model.) v 3 Sheets-Sheet 2.

No. 674,49l.

Patented May 2|, l90i.

C. W. BILFINGER. PROCESS OF DISTILLING WOOD FORTHE MANUFACTURE OF CHARCOAL AN-D SAVING OF BY-PRODUCTS. (Application filed i-ab. 24, 1900.

3 Sheets-Shot 3,

(No Ioqal.)

UNITED V STATES PATENT FFICE.

CARL WV. BILFINGER, OF SAVANNAH, GEORGIA, ASSIGNOR TO SOUTHERN PINE PRODUCT COMPANY, OF NEW JERSEY.

PROCESS OF DISTILLING WOOD FOR THE MANUFACTURE OF CHARCOAL AND SAVING 0F BY-PRODUCTS.

SPECIFICATIONformingpart of Letters Patent N o. 674,491, dated May 21, 1901.

Original application filed January 27, 1899, Serial No. 703,604. Divided and this application filed February 24, 1900. Serial No. 6,434. (No specimens.)

To all whom, it may concern:

Be it known that I, CARL W. BILFINGER, a citizen of the United States, formerly residing at Washington, county of Beaufort, and State of North Carolina, but now temporarily residing at Savannah, county of Ohatham, and State of Georgia, have invented certain new and useful Improvements in Processes of Distilling Wood for the Manufacture of Charcoal and Saving of the By-Products, of which the following is a full, clear, and exact specification, reference being had to the accompanying drawings, wherein Figure 1 is a longitudinal sectional view of my wood-distilling apparatus on line 1 1 indicated in Fig. 2, parts of the apparatus being shown in elevation. Fig. 2 is a sectional view on line 2 2 indicated in Fig. 1. Fig. 3 is a horizontal sectional view on line 3 3 indicated in Fig. 2.

The apparatus necessary for the carrying on of the process is more fully described in my United States Letters Patent No. 658,888, granted October 2, 1900, Serial No. 703,604, filed January 27, 1899, of which this applica tion is a subdivision.

The improvements embodied in my invention relate, first, to the conduct of the distillating process; second, to the manner of separating the various products of distillation from each other, and, third, to the manner of recovering the products and their preservation.

The objects of my improved process are, I

first, to decompose Wood into solids, volatile and non-volatile liquids, and gases; second, to separate these ingredients from each other, and, third, to prevent decomposition of any of the ingredients in the process of decomposing the raw material. These objects are accomplished by so directing the application of the heat to the retorts in which the distillation is carried on and by so regulating the degree of the heat according to the kind of raw material (wood) and according to the progress ofthe distillation, as hereinafter explained, whereby the extraction and separation of the various ingredients are accomplished in such successive steps, permitting the withdrawing of the diiferent ingredients at such stages of the process as are most favorable thereto and before they are subjected to any effect tending to decompose the same and by subsequent treatment, as hereinafter described, of certain of the products of distillation for the purpose of separating them from each other.

The apparatus used for myimproved process consists of an oven 0, built, preferably, of masonry, with a furnace H in its base, a series of fiues 2, J, J and J arranged between the rows of retorts A and in the inclosing walls, main flue H chimney M, two or more rows of retorts A, conduits 5, main conduit 6, separators B and C, scrubber D, and their connections, outlet-pipes G, tar-conduit F, and of the various hereinafter-described auxiliary devices.

Retorts A are preferably cylindrical vessels made of wrought-iron and covered on the outside withjackets 7, of fireproof clay or cement. Their tops are provided with charging-apertures 4, covered with removable lids 19 While the distillation is going on, and with concaved bottoms terminating in funnels a, connected by outlet-pipes G to the tar-conduit F. Lids 19 are secured in their place by braces 10 in a similar manner to the heads of boilers. Outlet-pipes G are closed with plugs or cocks 21. They are opened from time to time during the heat to discharge the tar accumulating in the concaved bottoms of the retorts.

The system of fines is shown in Figs. 1 and 2. Flues H, R, R, R and R connect furnace H directly with chimney M. Flues 2 are arranged in parallel and crosswise lines around and between the retorts. They are divided in sections and provided with dampers 3 and 3, operated by rods 8 from the outside of the furnace. By correspondingly setting these dampers the current of combustible gases flowing from the furnace H to chimney M is directed through the sections of flues 2. The combustible gases may be passed directly to the chimney or through fiues 2 around and between the retorts, and thus their action confined to one part of the retorts and the volume of heat increased or reduced. The fiow of the combustion-gases through the oven is indicated by arrows in Fig. 2 of the drawings.

A series of air-fines I I J J J &c., convey atmospheric air into various parts of the oven, supporting the combustion of the fuel and increasing the efficiency of the apparatus. These air-fines are so located that the air is heated while passing through them. Flue I is laid beneath the furnace in the ash-pit and terminates in the bottom of main flue H A branch I of this fine passes through bridgewall K, discharging fresh air into the furnace beyond the grate. The flow of the draft-air through this fine is regulated by damper 9, located beneath the ash-pit door. A second airline J is laid parallel with and immediately above the arch of the furnace. This flue divides into branches J J J 850., opening into successive sections of fines 2. Theinlet-flue J is provided with a slide, and by increasing or reducing the area of the opening the draft of air through these flues J J J &c., is regulated. The flow of air through the air-fines is indicated by arrows in Fig. 2 of the drawings.

Conduits 5 convey the volatile products of distillation through the main conduit 6 into the separator B. This separator is a hermetically-closed vessel, having an inclined bottom with a discharge-cock 11 set in its lower point and connected by pipe 13 with the condensing-separator O. This condensing-separator is also a hermetically-closed vessel with aninlet at the terminal of pipe 13 and an outlet at the pipe 15. A coiled pipe N, entering the separator O at n and leaving it at 72 is connected to a pump, drawing a continuous stream of cold water through the separators. In place of water any other cooling medium may be used. Pipe or conduit 15 starts horizontally from the lowest point of the condensing-separator C and branches off vertically toward the scrubber D. Some distance from the separator a downwardlypoinling tube 16, branching off of the conduit 15, is connected therewith. Through this tube, provided with stop-cock 17, the liquid products of condensation are conveyed from separator C to the refining apparatus. The incondensable gas passes through conduit 15 into scrubber D, which is connected by conduit V with a reservoir. (Not shown in the drawings.)

The process of distillation is carried on as follows: The material to be distilled is filled into the retorts, lids secured in their position, and the fire started in the furnace. Dampers 3 and 8 are keptclosed until the furnace-fire has attained sufficient headway. Then all sections of fines 2 are partly opened to admit the combustion-gases to the retorts until the temperature in the chamberis raised approximately to 280 Fahrenheit, which temperature is sufficient to liquefy all meltable ingredients of the material charged in the retorts.

At this stage of the process the liquefied ingredients could be withdrawn from the outlets provided in the bottoms of the retorts. As they are, however, in that state not separable from each other, a larger quantity of the hot furnace-gases are at this stage of the process admitted to the bottom part of the retorts, thus increasing the heat therein 'to nearly 400 Fahrenheit, or thereabout. This increase of heat in the bottom part of the retorts causes some of the liquids extracted from the wood to evaporate. These pass through conduits 5, connected with the top parts of the retorts A, and main conduit 6 into a receptacle B, which I designate as a gravityseparator, where the specific heavier of them are precipitated, and thus separated from the lighter. Then the valves 2l,closing the outlet-- pipes G, are opened to discharge the residue of the liquids accumulated in the bottoms of the retorts, which is mostly pure tar in its primary state, into the conduit F, conveying it to a receptacle. Next the sections of flues 2, surrounding the middle part of the retorts, are opened to admit the hot combustion-gases thereto until the temperature in that part of the chamber is raised to approximately 400 Fahrenheit. This rising of heat acting on the middle part of the retorts induces a further decomposition of the material charged in the retorts, during which the volatile ingredients pass as vapors through conduits 5 and main conduit 6 into the separator B, whereas the heavier liquid ingredients (tar) are discharged at the bottom of the retort-s and are conveyed through outlet-pipes G and conduit E into the tar-receptacle. When the flow of the tar has ceased, valves 21'are again closed and the dampers governing the lowermost sections of fines 2 are fully opened until the heat acting upon the bottom parts of the retorts rises to approximately 720 Fahrenheit. This temperature is necessary to decompose the residue of the material into gas and charcoal. During this stage of the process there is still some tar being produced, and this tar is from time to time discharged by opening valves 2i; but mostly only gas is produced, which escapes through conduits 5 .and 6 into separator B and from there through separator O and conduit 15 into scrubber D, wherein it is purified in the usual manner and finally conveyed into a reservoir. Some gas is being produced in the earlier stages of the process, and this passes, together with the evaporated oils and other evaporated liquid ingredients, through the aforementioned conduits from the retorts. The vaporous and gaseous products of the distilling process are collected in the separator B, wherein the specific heaviest oils are precipitated as liquids and withdrawn from time to time through the outlet 11, located near the bottom thereof. The vapors of the lighter oils and the gas pass through conduit 13 into the condensing-separator 0, wherein their temperature is reduced below the evaporating-point of the liquid products of distillation, and thereby the vapors of the lighter oil and other condensable products are reduced to liquids. These liquid products are Withdrawn through outletconduit 16, whereas the gas is conveyed into the scrubber D, wherein it is purified in the usual manner.

It is not always necessary to admit the hot combustion-gases to all sections of the oven to finish the distilling process, nor is it advisable to do so. The material charged in the retorts shrinks in the process of distillation and drops gradually into the lowest sections of the retorts, where as high a degree of heat is maintained as necessary to fully decompose it, whereas the upper parts of the retorts are filled with the vapors of the volatile products, which should not be overheated. It is essential for the successful accomplishment of the objects of myinvention that the raw material in the retorts be not subjected to an excessive heat. The purpose of this is toprevent decomposition of any of the primary products of the distillation. If tar is decomposed, the ingredients extracted therefrom affect detrimentally the gas produced in the distilling process and render it necessary to purify the same by a much more elaborate and expensive process than is necessary to purify gas which is free of such injurious ingredients. Also the by-products and most of all the turpentine are detrimen tally affected by absorbing such gaseous products of decomposition of tar in the retorts,. Furthermore, tar subjected to the process of decomposition loses its richest and most desirable ingredients, and consequently also its value, utility, and productive capacity for more valuable final products. Another evil effect of overheating the materiahcharged in the retorts is a partial decomposition of the charcoal. Oharcoahifsuperheated,is brought into a glowingstate and then discharges great quantity of carbonic acid, while in the same proportion it loses its heating capacity. This carbonic acid passes out with the other products of distillation and being absorbed by them to a considerable extent impairs their quality. A The process of purifying these products requires more complicated apparatus, more effort, and expenditure of labor and material than would otherwise be necessary. I have found through experiments that no carbonaceous raw materialsuch as wood, peat, due-requires to be subjected to more than approximately 76S Fahrenheit to obtain therefrom all ingredients that can be prudently and economically extracted and that the residue remaining after such material was subjected to such degree of heat for a sufficiently long period of time does not contain any more Valuable product than the residue itself and which could be extracted therefrom by distillation at a higher degree of heat. Some kinds of wood require a higher degree of heat to extract therefrom all extractible ingredients; but even in these cases it is preferable in the process of distilling such mate rial to li mit the heat, as hereinbefore said, because those ingredients requiring the highest degree of heat for extracting them are the least valuable. As shown in this explanation of my improved process, I accomplish the decomposit on of the raw material in successive stages. In the first period the moltable ingredients of the material are extracted through the application of moderate heat. These substances are then converted in vapors through application of a higher degree of heat to the lowest parts of the retorts and withdrawn while in such vaporous state and before any other products of distillation are developed. These moltable substances are the richest, most valuable, and also the purest products of the distilling process. As they are withdrawn from the retorts before any further decomposition of the raw material takes place, they are in almost pure state when reverted to their liquid or semiliquid state in the separators, as hereinbefore set forth, In this manner all expense for purifying these materials is saved and their rich quality preserved. It is well known in this art that such oils are easily discolored and reduced in quality through absorption of gases or through partial decomposition and that when once so affected their original purity, quality, and color cannot easily be restored and that every refining or purifying process heretofore known impairs their-quality. During the next following stage while a yet higher degree of heat is applied to the retorts the raw material is further decomposed by extracting its tarry substances, while at the same time the harder distillable oily substances are evaporated. The tar accu mulates in the bottom of the retorts, whereas the vapors of the oils, together with some gaseous substances, escape through the upper conduit-s into the separators. The vapors of the oily substances are again condensed in the separators; but it is clear that the products of this condensation are of less quality. These substances may be utilized for various purposes in the state as they are recovered. It is not necessary or economical to purify them. The tar is withdrawn before the next stage of the process commences. It is then richest in desirable ingredients and in its most favorable com position for use as raw material for valuable products. After all tar is withdrawn the last'stage of the process is entered upon. In this period the residue of the material is decomposed into charcoal and gas. The charcoal remains in the retorts, while the gas passes through the separators B and C, from which the liquefied products have been previously withdrawnflnto the scrubber D. It will thus be seen that all products of the distilled material are recovered separately from each other, that the richest and most valuable products are secured in almost pure state, and that none of the products is affected detrimentally, though the process of distillation is carried onto the point at which all recoverable ingredients of the raw material are extracted. There are no mechanical contrivances nor chemicals required for these purposes in my improved process, which is the most economical for distilling of wood or of any other carbonaceous vegetable raw materials. This process may be carried on in an apparatus which, as shown and described in this specification and in my aforesaid United States Letters Patent, is in its construction extremely simple and without the expenditure of any other material except the fuel required for heating the retorts.

I claim as my invention- 1. The herein-described process of distilling wood and other carbonaceous vegetable substances consisting first, in subjecting all material, charged in a hermeticallyclosed vessel or retort, to a heat of approximately 280 Fahrenheit, or thereabout; second, applying a higher heat, approximately 400 Fahrenheit to the portion of the material contained in the lower part of the retort, approximately one-third part thereof or thereabout; third, withdrawing the evaporated and gaseous substances produced by this partial distillation at this stage; fourth, increasing the heat applied to the lower section of the retorts to 768 Fahrenheit, or thereabout, and at the same time raising the temperature of the middle part of the retorts to about 400 Fahrenheit; fifth, precipitating all condensable substances produced at this stage of the process and withdrawing the same from the apparatus; sixth, withdrawing at this stage of the process the tar accumulating in the lower part of the retort, and all vaporous and gaseous substances from the upper part of the retort and seventh, separating all gaseous substances from the evaporated liquids and withdrawing the substances thus separated from the apparatus.

2. The method of decomposing carbonaceous vegetable materials and of recovering therefrom all valuable ingredients, consisting first, in subjecting the materials charged in hermetically-closed retorts, provided with separate outlets for liquid and for gaseous ingredients, successively to the action of the heats of varying intensity; second, separating the substances extracted at the successive periods of application of the heats; and third, withdrawing the separated substances from the apparatus, each separated from the others.

3; The method of decomposing carbonaceous vegetable materials and of recovering therefrom all valuable ingredients, consisting first, in subjecting the materialscharged in hermetically-closed retorts provided with separate outlets for liquid and for gaseous ingredients to the action of successive heats, increasing in intensity and extent of application; second, withdrawing from theretorts the liquid and gaseous products extracted from the distilled material at the successive periods and third, separating the evaporated substances into liquid and gaseous products by precipitation and condensation,and fourth, withdrawing from the apparatus the substances thus separated, each separated from the others.

4E. The process of distilling wood and other carbonaceous vegetable substances consisting of the following steps; first, heating the material, charged in closed retorts to approximately 280 Fahrenheit whereby its moltable ingredients are liquefied; second, applying to the lower part of the retorts approximately to one-third part thereof; a heat of approximately 400 Fahrenheit, while the other parts of the retorts are not exposed to any higher temperature than before, whereby the lighter of the liquefied ingredients are evaporated; third, withdrawing the vapors of the lighter ingredients and the remainder of the liquefied ingredients each separated from the others; fourth, applying to the middle part of the retorts'a heat of the same intensity as heretofore applied to the lower parts thereof; fifth, withdrawing the gases and vapors of liquid substances produced in this period of the process from the retorts,

each separated from the others; sixth, increasing the intensity of heat applied to the lower parts of the retorts to approximately 720 Fahrenheit, whereby the solid residue of the material remaining in the retorts is converted into charcoal and gas; seventh, separating the evaporated liquid and gaseous products of the distillation withdrawn from the retorts, by passing the same successively through a closed vessel having two outlets, one on top and the other at the bottom thereof, wherein the specific heavier liquids are precipitated, and then passing the remainder through another closed vessel wherein the temperature of the vapors and gases is reduced below the evaporating-point of the liquid products; and finally, withdrawing the remaining gaseous products of the distillation from the apparatus.

CARL W. BILFINGER. Witnesses:

RICHARD ROBINSON, P. L. GRINER. 

